(a) Technical Field
Embodiments of the present disclosure are directed to a three-dimensional (3D) display device.
(b) Discussion of the Related Art
In general, a display device displays a two-dimensional (2D) planar image. However, as a demand for 3D stereoscopic images has increased in fields such as gaming and movies, 3D stereoscopic images can now be displayed using a display device.
A stereoscopic image display device divides an image into a left-eye image and a right-eye image that have binocular disparity, and respectively provides them to a left eye and a right eye of an observer. The observer recognizes the left-eye image and the right-eye image through both eyes, and the images are combined in the brain such that a stereoscopic image is perceived.
One way to make a stereoscopic display device display a stereoscopic image uses linearly polarized stereoscopic spectacles to divide the left-eye image from the right-eye image, however, spectacles must be worn.
To solve this requirement, a method has been proposed that does not involve wearing spectacles. Based on the type of lens element that divides the image, such a method includes a lenticular type, a parallax type, an integral photography type, and a holography type. In particular, a lenticular type of stereoscopic image display device has been studied.
A lens used in the lenticular device may be a convex lens or a Fresnel lens. A Fresnel lens is thinner than a convex lens. A Fresnel lens has a plurality of circular arcs on a surface thereof. The circular arcs of a Fresnel lens refract light.
A liquid crystal lens that can realize a Fresnel lens by controlling director distribution of liquid crystals through an electric field has been developed. A liquid crystal lens includes an upper substrate, a lower substrate, and a thick liquid crystal layer between the upper substrate and the lower substrate. The liquid crystal lens includes a plurality of electrodes, and each electrode may be supplied with a different voltage to control the liquid crystal directors.